The inventors have previously developed procedures for magnetic targeting of iron oxide-containing, magnetically responsive, biodegradable nanoparticles containing therapeutic agents to permanently deployed superparamagnetic stents in vivo. The feasibility of this approach has been demonstrated for delivering drugs, gene vectors and cell therapy. The inventors have also shown that targeting of MNP to permanent stents can be enhanced by application of a relatively uniform magnetic field. The following patents and published patent applications, which describe various aspects of magnetic targeting procedures, are incorporated herein by reference: U.S. Pat. No. 7,846,201, U.S. Pub. No. 2009/0216320, U.S. Pub. No. 2009/0082611, U.S. Pub. No. 2010/0260780, and International Pub. No. WO 2004/093643.
Targeted delivery of magnetic nanoparticles (MNP) has been performed by applying a uniform magnetic field to a permanent stent composed of a superparamagnetic material. Permanent stents have been used as targets based on the assumption that permanent implants ensure long term retention of MNP at the target site. Unfortunately, this approach is not an option for sites that do not have a permanent implant in place, but require treatment.